Digital television, popularly referred to as DTV, is an enhanced television system capable of transmitting and receiving digitized signals, displaying digital images and playing digital audio. While some of these features may be present in current analog television systems such as national television standards committee (NTSC), sequential couleur avec memoire (SECAM) and phase alternate line (PAL), the combination of digitized transmission, reception, video and audio distinguishes digital television from current analog television systems.
The technology utilized by digital television is superior to current analog television systems and utilizes scarce bandwidth in a more spectrum efficient manner. In this regard, digital television allows more channels containing more information to be broadcasted within an equivalent bandwidth utilized by current analog television systems. Accordingly, any excess bandwidth can be re-allocated for use by other types of communication systems. Broadcasters utilizing digital television systems are therefore, capable of providing over-the air television signals containing higher picture resolutions than current analog broadcast television systems. For these reasons, Congress had mandated that current broadcast television service must, in time, be completely converted to digital television.
In order to provide these high resolution television signals, digital television systems utilize various video and audio compression techniques, for example, moving picture experts group (MPEG). MPEG is a joint committee of the international standardization organization (ISO) and the international electrotechnical commission (IEC), and is generally referred to as ISO/IEC JTC1/SC29/WG11. MPEG includes various charter groups, each of which contains a diverse representation from among computer, telecommunications, television, cable, satellite, and other industries worldwide. The charter of various MPEG video and audio groups is to develop compression standards for full-motion video, associated audio and their multiplex for digital storage media. These compression standards are also utilized by digital cable television systems and digital satellite systems. Although compression standards are promulgated by the various groups, transmission and encryption or conditional access techniques are not specified in the MPEG standards. Accordingly, system designers and integrators may freely determine and implement their own transmission or conditional access techniques.
Additionally, in some conventional audio/video processing systems, audio/video data such as movies are vulnerable to piracy and require protection against illegal copying. The loss associated with piracy and unauthorized copying is greatest in high value movies and video programs. Since uncompressed digital video in clear form can be used to create perfect copies of the high value programs in particular, it is necessary to enable the protection of uncompressed video with copy protection technology. To protect against piracy or unauthorized copying, video data such as high value video content is sometimes compressed and encrypted before it can be accessed in memory and storage devices. Video decoding and de-compression systems generally utilize frame buffers for motion prediction, which may provide enhanced picture quality. Video images or pictures stored in these frame buffers are un-compressed and clear. Accordingly, attackers or hackers may utilize various schemes to access these buffers and copy the video images.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.